You can create pre-defined 3D geometric shapes called primitives in Maya. Primitives can be used as-is or as a starting point for 3D modeling.
Some examples: you can create a sphere primitive and then scale it so it appears more elliptical. You can detach half of a sphere to make a dome. You can create a plane to use as a floor in your scene. You can also use Boolean features to intersect primitives with each other to produce new shapes.
The primitive creation options are located in the Create menu. For example, Create > Polygon Primitives > Cube.
The options for each primitive type are selected by choosing the option box beside the primitive’s name. For example, Sphere > 
, Cube > , Cone > , and so on.
There are three ways to create polygon primitives: